Common in more clingy teenagers. A boy or girl who just wants a girlfriend/boyfriend so badly that they will date the first remotely attractive person who comes along.
A lot of people don't really look specifically for good personalities or morals, but whether or not it would be fun to make out with them.

When a girl goes to a party and asks "Will anyone make out with me?!" and everyone says no but she keeps persisting, she is desperate.

The state of being so lonely and so insecure, due to lack of esteem, that you will date/marry or have sex with anyone. You dont care weather or not it is bad for you, but only how "good" it feels to have somebody you think is compatible with you and likes you for yourself. You decieve yourself into thinking that this person makes you happy, when in reality it's only the feeling of love that makes you happy. Instead of waiting for the right person to come along, you settle for someone who is much less ideal for you and can make your life even more miserable.

In being desperate, you deceive yourself into thinking that this person makes you happy when, in reality, it's only the feeling of love that makes you happy. You are so desperate for love, attention, and affection, that you resort to lowering your standards. You may even "settle" for an abusive relationship, just for the sake of not being alone. The state of being desperate is a dangerous thing.

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In dire need of something. Usually associated with people trying to get some from other people. Desperate people is commonly a catch 22. Desperate people usually don't get what they want, thus they are always desperate.

Sue is so desperate to get some guy that she turns them off by being desperate.